1. Field of the Invention
The present invention relates to an allocation control technology for allocating storage regions in a storage device.
2. Related Background Art
In large-scale storage devices such as disk array devices, modules are provided for creating storage regions, which are used by computers to store information inside the storage devices. However, the modules for creating storage regions have different interfaces and/or request formats depending on the vendor that manufactures each storage device. For this reason, when storage devices made by different vendors are combined, an administrator of the storage devices must learn different interfaces and/or request formats of various vendors, which is a major problem in large-scale computer systems. To address this problem, DMTF (Distributed Management Task Force) devised CIM (Common Information Model) and WBEM (Web-Based Enterprise Management), which define interfaces and request formats when creating storage regions in storage devices. By using interfaces defined by CIM, storage regions can be readily created using a standardized method in storage devices manufactured by different vendors. Interfaces and request formats for creating storage regions and defined by CIM utilize “hints” to create storage regions, as follows (excerpted from
Device27_StorageServices.mof)://=====================================================// StorageSettingWithHints//======================================================[Experimental, Version (“2.7.1”), Description ( “This subclass of StorageSetting allows a client to specify ” “‘hint's for optimization of the volume performance. The effect ” “of these hints is implementation dependent.”) ]class CIM_StorageSettingWithHints: CIM_StorageSetting { [MinValue (0), MaxValue (10), Description (  “This hint is an indication from a client of the importance ”  “placed on data availability. Values are 0=Don't Care to ”  “10=Very Important.”) ] uint16 DataAvailabilityHint; [MinValue (0), MaxValue (10), Description (  “This hint is an indication from a client of the randomness ”  “of accesses. Values are 0=Entirely Sequential to ”  “10=Entirely Random.”) ] uint16 AccessRandomnessHint; [MinValue (0), MaxValue (10), Description (  “This hint is an indication from a client of the direction ”  “of accesses. Values are 0=Entirely Read to ”  “10=Entirely Write.”) ] uint16 AccessDirectionHint; [Description (  “This hint is an indication from a client of the optimal ”  “access sizes. Several sizes can be specified.”),  Units (“MegaBytes”) ] uint16 AccessSizeHint []; [MinValue (0), MaxValue (10), Description (  “This hint is an indication from a client how important ”  “access latency is. Values are 0=Don't Care to ”  “10=Very Important.”) ] uint16 AccessLatencyHint; [MinValue (0), MaxValue (10), Description (  “This hint is an indication from a client of bandwidth ”  “prioritization. Values are 0=Don't Care to ”  “10=Very Important.”) ] uint16 AccessBandwidthweight; [MinValue (0), MaxValue (10), Description (  “This hint is an indication of the importance the client ”  “places on the cost of storage. Values are 0=Don't Care to ”  “10=Very Important. A StorageVolume provider might choose ”  “to place data on low cost or high cost drives based on ”  “this parameter.”) ] uint16 StorageCostHint; [MinValue (0), MaxValue (10), Description (  “This hint is an indication of the importance placed on ”  “storage efficiency by the client. Values are 0=Don't Care ”  “to 10=Very Important. A StorageVolume provider might choose ”  “different RAID levels based on this hint.”) ] uint16 StorageEfficiencyHint;};
By using “hints,” storage regions to be created can be designated abstractly. Due to the fact that the creation of storage regions can be instructed using “hints,” an advantage of being able to provide a standardized request format, even if the hardware configuration of storage devices by various vendors is completely different, can be gained.
Also, there is a known method for controlling bands between computers and storage regions. Furthermore, RSVP (Resource ReSerVation Protocol (RFC2205)) is devised by the IETF (The Internet Engineering Task Force) for IP (Internet Protocol).
In order to create storage regions with band control based on prior arts, first an interface and a request format defined in CIM devised by DMTF, as well as hints, are utilized to create storage regions. Hints designated by an administrator include design concepts (policy) as to how storage regions created should be utilized by computers. Next, bands are set in a storage device in order to set bands between the computers and the storage regions. However, since band setting on storage devices is not defined in CIM defined by DMTF, the bands must be set by fully utilizing interfaces and request formats that differ by vendors. Furthermore, setting parameters for band control must be selected and set, so that they would satisfy hints that were designated when storage regions were created. Consequently, the administrator must have the know-how to select band setting parameters that correspond to hints that were provided when storage regions were created, which means that the administrator requires high-level knowledge. Furthermore, there is a risk that the administrator would select wrong band setting parameters, and there is no way to prevent this.